Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
Biosens Bioelectron. 2013 Dec 15;50:486-91. doi: 10.1016/j.bios.2013.07.017. Epub 2013 Jul 17.
An integrated magnetic nanoparticles-based test strip immunosensing device was developed for rapid and sensitive quantification of phosphorylated butyrylcholinesterase (BChE), the biomarker of exposure to organophosphorous pesticides (OP), in human plasma. In order to overcome the difficulty in scarce availability of OP-specific antibody, here magnetic Fe3O4@TiO2 nanoparticles were used and adsorbed on the test strip through a small magnet inserted in the device to capture target OP-BChE through selective binding between TiO2 and OP moiety. Further recognition was completed by horseradish peroxidase (HRP) and anti-BChE antibody (Ab) co-immobilized gold nanoparticles (GNPs). Their strong affinities among Fe3O4@TiO2, OP-BChE and HRP/Ab-GNPs were characterized by quartz crystal microbalance (QCM), surface plasmon resonance (SPR) and square wave voltammetry (SWV) measurements. After cutting off from test strip, the resulted immunocomplex (HRP/Ab-GNPs/OP-BChE/Fe3O4@TiO2) was measured by SWV using a screen printed electrode under the test zone. Greatly enhanced sensitivity was achieved by introduction of GNPs to link enzyme and antibody at high ratio, which amplifies electrocatalytic signal significantly. Moreover, the use of test strip for fast immunoreactions reduces analytical time remarkably. Under the optimized conditions, the developed device shows a broader linear response over the concentration of OP-BChE from 0.05 nM to 10 nM within 15 min, with a detection limit of 0.01 nM. Coupling with a portable electrochemical detector, the integrated device with advanced nanotechnology displays great promise for sensitive, rapid and on-site evaluation of OP poisoning.
一种基于磁性纳米粒子的测试带免疫传感装置被开发出来，用于快速灵敏地定量检测人血浆中磷酸化丁酰胆碱酯酶（BChE），这是接触有机磷农药（OP）的生物标志物。为了克服 OP 特异性抗体稀缺的困难，这里使用了磁性 Fe3O4@TiO2 纳米粒子，并通过插入装置中的小磁铁将其吸附在测试带上，通过 TiO2 和 OP 部分之间的选择性结合来捕获目标 OP-BChE。进一步的识别是通过辣根过氧化物酶（HRP）和共固定化在金纳米粒子（GNPs）上的抗 BChE 抗体（Ab）完成的。通过石英晶体微天平（QCM）、表面等离子体共振（SPR）和方波伏安法（SWV）测量，表征了 Fe3O4@TiO2、OP-BChE 和 HRP/Ab-GNPs 之间的强亲和力。从测试带切割下来后，在测试区域下使用丝网印刷电极通过 SWV 测量所得免疫复合物（HRP/Ab-GNPs/OP-BChE/Fe3O4@TiO2）。通过引入 GNPs 以高比例连接酶和抗体，大大提高了灵敏度，显著放大了电化学生物信号。此外，测试带的使用可显著缩短免疫反应时间。在优化条件下，该装置在 15 分钟内对 OP-BChE 浓度从 0.05 nM 到 10 nM 表现出更宽的线性响应，检测限为 0.01 nM。与便携式电化学检测器耦合，该集成装置结合了先进的纳米技术，有望用于敏感、快速和现场评估 OP 中毒。
